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Consider the haplotype for the bacterial lac operon: i-o+z+. there is also a plasmid with the haplotype: i+ocz-. for all of the questions below, assume there is no glucose and no inducer. repressor protein will be bound to both operators in this cell:

a. True
b. False

2 Answers

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The question is false.
User Rash
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Ans. 'false.'

Lac operon or lactose operon in bacteria represents a set of genes, responsible for the transport and metabolism of lactose by bacterial cells.

The 'i⁺' represents a wild-type regulatory gene, which expresses regulatory protein and transcription is regulated, while 'i⁻' represents a mutant regulatory gene that cannot make regulatory protein.

The 'o⁺' represents a wild-type operator sequence that can be repressed by a functional regulatory protein, while 'oc' represents a defective operator, by which the repressor protein cannot bind and thus, transcription is always on (constitutive expression).

The z⁺ represents wild-type structural gene that gets expressed, when transcription is on, while z- represents mutant and defective structural gene, thus, no lactose metabolism will occur.

Hence, in given bacterial cell, the repressor protein cannot not bind to both operator as operator of 'i+ocz⁻' haplotype represents a constitutive operator, by which repressor protein cannot bind and operon is always on.

Thus, the given statement is 'false.'

User Seebiscuit
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